Gerald the cuddly duck

ZFS is a very promising filesystem that Sun developed for SunOS. When they released the source code it got ported to Linux. A lot of people speak very highly of it, so I decided to give it a go before committing to use it in a real installation.

To start with, I just tried a simple zpool on a removable hard drive. I played with datasets, volumes and snapshots and it all worked really nicely. I even played around with having qemu mount volumes from it. I was hugely impressed.

Then I decided I wanted to unplug the drive. I did zpool export and it said it was busy. I closed everything I could find. I tried zfs unshare, zfs unmount, lsof and so on. No offenders showed up. I tried zpool export -f — still no joy.

At this point, /proc/mounts was showing no ZFS-related filing systems. /dev no longer contained the ZFS-volume-related devices. I could see no sign of the zpool except via ZFS's own commands, which were still stubbornly refusing to export the pool.

Eventually, I gave up and simply pulled the drive. Oh boy was ZFS unhappy! Now every zfs or zpool invocation wedged so hard not even kill -9 could terminate it.

I tried rmmod zfs without any real expectation it would deign to terminate; I was not disappointed.

Eventually, I rebooted. But ZFS seemed to have got in such a pickle that it didn't shut down cleanly. Cue an extremely painful reboot process.


This makes me sad. On the one hand, ZFS is a lovely filing system with a lot of potential; on the other, bricking a system so hard at such slight provocation is almost unforgivable. )-8

(Long time no post! I've no idea how many people are still reading, but this is as good a place as any for me to post this so I can refer interested parties to it.)

I visited the UK Games Expo yesterday.

Things I bought

Arboretum, sort of a set-collecting card game, but with three or four very unusual twists. I've played it twice and want to play it more.

Paco Ŝako. Ignore all the cobblers about peace, friendship and collaboration: this is a Fairy Chess variant with three key features:

• You never take pieces; if you move onto a square occupied by an enemy piece they become paired and either player may move the pair as a unit, according to the rules of their half of the pair.
  
• You can move onto a square occupied by a union. In this case, you liberate your piece which was previously in the union and move it away from that square. If that in turn moves onto the space occupied by a second union then you get a chain reaction, which is both cool and a really alien concept to get one's head around after a lifetime of playing regular chess.
  
• The pieces are specially designed to pair up nicely. They're beautiful and almost worth owning merely as a work of art.

The pieces are available in a variety of colours. After much deliberation, I opted for yellow and green, because they go together OK as a dark-light pair, and they're two colours of piece that I don't yet have in my Penultima set. (-8<

Half a dozen Fudge dice, also for Penultima.

A larger cloth bag for my Acquire set because, inexplicably, not all the tiles can fit in the supplied one.

The Oink Games version of Riner Knizia's classic Modern Art. It's so refreshing that Oink sells fully-fledged board games in the kind of tiny boxes normally reserved for card games. Strictly speaking, I didn't buy it at the show; I merely talked to people on their stand and confirmed licensing restrictions mean they can't sell it here. So I bought it from amazon.de while I was at the show.

Echidna Shuffle is adorable: a pick up and deliver game where you move huge plastic echidnae around the board. It's basically a kids' game, but I'm itching to have a go anyway. I didn't buy this myself, but I did persuade my friend Charlie to get a copy, which also works.

Things to try before I buy

Bärenpark: Compete to make beautiful zoo enclosures for bears. Looks like a thin thematic skin over a game of tesselating polyominoes. It's encouragingly well rated, and it's by Phil Walker-Harding of Imhotep and Sushi Go fame.

I am not a fan of Richard Garfield. Don't get me started on Richard Garfield. However, Bunny Kingdom is tolerably playable, with fewer glaring flaws than most of his stuff. I'd play it again. I'm not personally about to buy the In the Sky expansion, but it exists and might be interesting.


Matt Leacock's Forbidden Island and Forbidden Desert are perfectly playable, good, solid co-operative games. His next game in the series is Forbidden Sky, which I was expecting to be merely more of the same. Now I've seen it in the flesh, though, it looks like a dramatically different game, with some interesting aspects to its physrep. I want to investigate further.

The Fox in the Forest has eye-catchingly beautiful artwork, and a reasonable BGG rating. So far, that's all I know about it; I hope the game itself is good, because I want to spend more time with those cards some day. (-8

I own and like Imhotep. It plays fine with two, but now Phil Walker-Harding has produced Imhotep: the Duel. I've looked at it in detail, and seems to be a solid and interesting game with considerable stylistic similarities to Imhotep. I want to play it. I might have bought it on spec, but I simply don't get enough opportunities to play two-player games these days.

From the description, Letter Jam sounded like a word version of Hanabi. It's currently late in prototyping and the rulebook isn't online because it's not finalised, but I managed to browse a draft: aside from being a co-op with the notion of having other players able to see your cards while you can't, it has nothing else whatever in common with Hanabi. It seems to test the ability to make long words using a specified subset of the alphabet, the ability to identify a word that has missing letters, and just a touch of solving 5-letter anagrams. Intriguing. I tend not to get bogged down actually playing the games at the Expo, but that's definitely one to try once it's properly available.

Continuing the Phil Walker-Harding theme, there is also Sushi Roll, a wonderfully-named dice game based on Sushi Go. That's all I know for now...

Tokyo Highway is a few years old, but I'd not encountered it before. And it's not especially well loved in the BGG ratings, either. But they had a hyuuge version of it at the show that I could hardly not notice - so congratulations to their marketing team. It's a very spatial game, which looks like it might be right up my street.

Dishonourable mention

I've no idea about the gameplay, but in all other respects Ticket to Ride: London annoys the hell out of me. The artwork has a vexing " 'allo Mary Poppins" quality to it, and is riddled with anachronisms. (This isn't just me being overly sensitive when it's my own country they're creating a pastiche of; the UK map's artwork was entirely tolerable.) The choice of locations, and of paths between locations, makes no sense whatever; I somehow doubt Alan Moon has ever visited London, or knows very much about it. Hohum.

Pandemic: Rapid Response isn't by Matt Leacock, and appears to have nothing in common with the rest of the Pandemic family of games. This means it's just some random real-time game of no especial interest, and I'm worried Z-Man may have begun to milk the format. )-8

There's a lot of bile in the US on the subject of gun control right now, most of it relatively grim and uninteresting.

One particular aspect caught my eye, though. Firstly, some pro-gun people said things along the lines of "you aren't a gun user; you're not qualified to have an opinion on gun safety". To which some anti-gun people retorted "you don't have a uterus; you're not qualified to have an opinion on abortion".

Given that gun control and abortion do indeed seem to polarise along pretty much the same axis in the US, that response strikes me as largely fair.

But…

Would pro-abortion, anti-gun people be happy if the pro-gun, anti-abortion people said "OK, we hereby withdraw our stance on abortion. Now you can't complain about guns"?

What if they instead said "OK, yes, you can express a view on guns. Now you can't complain about our expressing a view on abortion"?

I have the impression many pro-abortion, anti-gun people feel they have every right to protest about guns, but think the pro-gun, anti-abortion people should shut up about abortion. Isn't that the mirror-image problem?


In reality, to quote Ben Goldacre, I think you'll find it's a bit more complicated than that. Some people are so heavily invested in an issue they find it difficult to take a dispassionate view; some people are so divorced from an issue they can't take an informed view.

On gun control, abortion and so many other issues, it would be nice if both sides could acknowledge this and move on.

I'm seriously missing the good old Livejournal days. For the most part conversation was lively yet temperate and cogent.

I finally gave up and joined Twitter and Facebook; it has to be said that both are pretty grim in their respective ways.

While there's a certain art (or was until they doubled the length of tweets) to constructing something concise and pithy, to a first approximation Twitter appears to consist of:

• Celebrities saying a few interesting things
  
• Arseholes of every stripe screaming abuse at one another
  
• Jokes and memes
  
• A few friends saying things I disagree with and would like to discuss, but daren't tackle via Twitter

Meanwhile, Facebook is full of people who've friended everyone they know, and are now carefully trying to project a sanitised image of universal acceptability. They don't want to get political because their racist uncle bought an iPad last year, and they can't say anything too lewd because they don't want their boss's children reading about sex-toy wholesalers. Facebook's algorithms show you the stuff people hit "like" on the most, which rapidly descends to the lowest common denominator. Oh, and conversations are only threaded one layer deep, so… yeah.


Livejournal used to be a platform for having conversations with the people you wanted to have conversations with. Not your friends. Not your relatives. Not famous people. Debaters. Raconteurs. Conversationalists.

That's largely gone, now. The realisation of how much I feel the lack has only gradually crept up on me. Somehow, slowly but surely, posting stopped feeling like it was worth the bother. Result: I'm now staring at a six-month-long gap in my blog. )-8


A few weeks back, I was chatting to joebunny who remarked about my recent radio silence. I said some of what I'm saying here now. Three or four of us all agreed that we missed Livejournal. All it would take for blogging to flourish again is for people to blog again; I wonder if that could happen?

Suppose you wish to designate an option to a piece of hardware. You could stick down a little EEPROM, but maybe you'd prefer to make links, or join PCB tracks, without any active componentry.

You have Gnd, and N configuration lines each with weak pull-up. How many different values can you represent?

The most utterly naïve solution would be to encode N options by tying one of the lines to ground.

The marginally less naïve solution — and one that's very widely used — is to encode 2^N options by tying any subset of the lines to ground.

However, if the configuration lines are independently bidirectional you can also tie them to one another. Denoting a ground connection by 0, n/c by 1 and commoned groups of lines by A, B, C, etc. the options with 2 lines become: 00 01 10 11 AA. With 3 lines: 000 001 010 011 100 101 110 111 0AA A0A AA0 1AA A1A AA1.

With 4 lines, things explode rather:

• 0000 0001 0010 0011 0100 0101 0110 0111 1000 1001 1010 1011 1100 1101 1110 1111 (=16)
  
• AA00 A0A0 A00A 0AA0 0A0A 00AA, AAA0 AA0A A0AA 0AAA, AAAA (=11)
  
• AA01 A0A1 0AA1 AAA1, AA10 A01A 0A1A AA1A, A1A0 A10A 01AA A1AA, 1AA0 1A0A 10AA 1AAA (=16)
  
• AA11 A1A1 A11A 1AA1 1A1A 11AA (=6)
  
• AABB ABAB ABBA (=3)

…for a total of 52 options.


More generally, the number of options is B_N+1, where B denotes a Bell number. My maths is rusty, but it looks like that grows faster than exponentially with the number of pins.

Is this a technique people actually use? Is there some reason I'm overlooking why it's a bad idea?

I mean, OK, I'll probably just use an EEPROM, but…

It's been two months now since the One Love Manchester concert. I'm still going back and watching this video every few days. And I'm still crying every time I do.

I was already quite impressed by Ariana Grande. She seemed like a genuinely lovely person, though I was cynically aware that a bit of careful PR could curate a favourable public image. Her response to the Manchester bombing, however was hugely impressive, and evinced the kind of grace and compassion that's beyond fakery.

The decision by Parrs Wood school to release a charity single in the wake of the bombing was inspired, as was the decision for them to perform at One Love Manchester, on the same stage as an impressive hastily-convened lineup of international megastars.

In the normal course of events, if you catapulted a twelve-year-old from the relative obscurity of a school choir into an audience of fifty thousand at Old Trafford with tens of millions more around the world watching live on TV, and they started crying, that would be a pretty awkward moment. Not this time!

Ariana hugs her with sincere tenderness, and it works. The look in Natasha's eyes at the 2m31s mark is beautiful to see. What's more, the crowd feels exactly the same way, and is entirely supportive of both of them.

Natasha has since spoken to Manchester Evening News, and clearly views the experience extremely positively.

It's also clear that Ariana Grande has a prodigious talent. When I pause to think about what's going on there, she's performing one of the biggest gigs of her life at one week's notice, she's juggling her own emotions, she's looking out for Natasha and she still sings like that!

I've been thinking again about the deck of many things idea I mooted a couple of years ago.

Indeed, having transcribed the details from the sheet of paper with an ominous "MkVIIIb" scribbled in the corner, I find that the result is quite cool, actually. [LibreOffice .ods]

Having gone through a phase of throwing everything at the concept and seeing what would stick, I was in a mess with a monstrous number of cards. Then I realised playing cards don't have to be rotationally symmetric. My new plan is for cards where ¾ is given over to the top section and the remaining ¼ is separate thing, the other way up. With very minor exceptions, I've managed to arrange that each game uses exclusively tops, or exclusively bottoms; this means the back of the cards can also lack rotational symmetry, making it easy to get them all the same way up.

I'm semi-seriously pondering throwing this idea through the Kickstarter mill. Since this is just two double-decks of playing cards, once a snazzy design is complete manufacturing and fulfilment should be nearly zero risk.

Alternatively, I just cobble together something less pretty and make myself some decks at Printer's Studio.

The overall concept

Ignoring a few specials, and the bottom sections of cards, I've settled on twelve suits.

They are: ♠♤♣♧♥♡♦♢▼▽●○

(The ▼▽ symbols are placeholders. They're supposed to represent round-bottomed shields, like Spanish heraldic ones.)

The suits would be represented by the background colours of the card top sections, with mainly white text. This is partly for fun, partly because the colours signify rather more than with a normal deck, partly so it's distinctive from the black-on-white bottom section of the card. I'm aware that would make it a little easier for other players to discern something about your cards if they glimpse one, but this isn't going to be used for tournament Bridge or casinos. (-8

As well as just being twelve miscellaneous suits for various purposes, the suits have various groupings that I'm hoping will be relatively intuitive:

• Ignoring outline/solid, to get six larger suits:
  • Spades: ♠♤
    
  • Clubs: ♣♧
    
  • Hearts: ♥♡
    
  • Diamonds: ♦♢
    
  • Shields: ▼▽
    
  • Circles: ●○

By outline/solid:

• Dark/solid: ♠♣♥♦▼●
  
• Light/outline: ♤♧♡♢▽○

By shape of base/colourway:

• Pedestal/black: ♠♤♣♧
  
• Pointy/red: ♥♡♦♢
  
• Rounded/blue: ▼▽●○

A rainbow: ♥♦♢♣●▼▽

As a baseline expectation, each of those sets has the ranks 1-10 appearing once each. A painstakingly-chosen subset of them then have aces, jacks, cavaliers, queens, kings, zeros and/or ranks higher than 10, as required for the various games.

Picture cards, of course, only need their image one way up. This should create a certain amount of extra space on them. On JQK, these are used to add the +2,Ø,⇄ symbols needed by UNO. Similarly, there are twelve jokers, each with an additional symbol in its top section.

Below the rank and suit in each top corner, there will sometimes be a third index. This will be one of:

• A repeater for the additional symbol on a picture card or joker
  
• Action symbols for Red7 on rainbow-coloured 1,3,5,7
  
• Suit values for playing Pit

The bottom sections of cards are variously used for:

• Numbers 0-104 (with 6 nimmt! scoring marks)
  
• Pile base cards needed for The Game
  
• Love Letter
  
• Mahjong honours and bonuses
  
• A full set of chess pieces in each of black and white
  
• A couple of dozen unused (must try harder!)

The specials

As well as things fitting that regular pattern, there are 27 irregular cards across three groups:

• A "suit" of ten rainbow cards, for Hanabi, but not with the normal 1-10 ranks.
  
• An extra 1 in each of five special suits. For each of the suit pairs other than spades, this is a suit half-way in colour between light and dark, denoted by an outline symbol with a dot in the middle. This is also for Hanabi.
  
• Twelve Jokers

The games we play

This quadruple deck, 216 cards, is sufficient to play: No Thanks!, The Game, 6 nimmt!, Twins, Pairs, Arboretum, Cockroach Poker, Red7, Love Letter, Parade, Battle Line, Coloretto, Hanabi, Five Crowns, Pit, The Great Dalmuti, UNO and Mahjong. In addition, it can form a simple 52-card deck, a 104-card double deck, a 104-card eight-suited deck, a 62-card 500 deck or a French Tarot deck. It can also be used to randomise 2d6, d%, dominoes or Chess pieces. At a pinch, it might even be possible, though ergonomically awkward, to use it to play dominoes or Chess.

That's 18 games which normally need specialist decks, plus at least five varieties of deck, and a few little bonus features. And maybe I'll think of something to do with the remaining 26 bottom sections.

As a finale, when I noticed everything fitted with one card to spare I decided that it made sense to have a round dozen jokers, not 11, and that the twelfth joker should be… a badger. This deck would be awesome for Mao!

Hmm. Livejournal requiring agreement to new T&C in order to continue using Livejournal. Shady, but there we go.

However, here's the thing: I have a permanent account. By my understanding, that means I've paid them to continue providing me with service for as long as they remain a going concern, without requiring anything more of me, such as acceding to new T&C. Can I not nobble them?

At the very least, it'd be nice to recover the fee I paid for a permanent account, if they're not going to provide me with an account permanently!

I was window shopping in IKEA today, and made an impulse purchase of quite a nice looking cordless drill/screwdriver. I do have an ancient Black and Decker cordless screwdriver, but it's not a pistol-grip, it's not a drill and it uses obsolescent VersaPak NiMH batteries which make it pointlessly heavy.

My decades-old mains hammer action power drill is still going strong and I'll continue using it for heavy-duty work, but I'm looking forward to having something cheap and cheerful with which to drill pilot holes, etc.

Anyway, the instructions say "WARNING: RISK OF TRAPPING Do not hold the front sleeve of the chuck with one hand at the same time as you open or close the jaws of the chuck with the help of the drill/driver's motor." Provided you're not an idiot and you use a low speed and torque setting, is this a real problem? Trapping what, where? Are they just covering themselves, or am I being overly blasé about a significant risk?

Of course, I'd already done that several times without incident before I bothered to read the instruction manual…

So here's a dumb question, which I'm startled I've lived quite so many decades without asking before:

When we cook food, which is needed: elevated temperature or an actual input of thermal energy?

I'm sure in almost any cooking appliance a lot of the energy ends up as thermal loss, but if we made an oven out of something swanky like aerogel, then got food up to temperature, if we killed the heat would the food gradually cool down as it cooked, or retain its temperature?

Wikipedia is being surprisingly unhelpful. My question may boil down (geddit?) to: "What are the thermodynamics of the Maillard reaction?"